split up the metadata parser

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13637 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 118 insertions, 0 deletions

diff --git a/apps/metadata/mpc.c b/apps/metadata/mpc.c
new file mode 100644
index 0000000..60e8202
--- /dev/null
+++ b/apps/metadata/mpc.c
@@ -0,0 +1,118 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 Dave Chapman
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <inttypes.h>
+
+#include "system.h"
+#include "id3.h"
+#include "metadata_common.h"
+#include "logf.h"
+#include "replaygain.h"
+
+bool get_musepack_metadata(int fd, struct mp3entry *id3)
+{
+    const int32_t sfreqs_sv7[4] = { 44100, 48000, 37800, 32000 };
+    uint32_t header[8];
+    uint64_t samples = 0;
+    int i;
+    
+    if (!skip_id3v2(fd, id3))
+        return false;
+    if (read(fd, header, 4*8) != 4*8) return false;
+    /* Musepack files are little endian, might need swapping */
+    for (i = 1; i < 8; i++) 
+       header[i] = letoh32(header[i]); 
+    if (!memcmp(header, "MP+", 3)) { /* Compare to sig "MP+" */
+        unsigned int streamversion;
+        
+        header[0] = letoh32(header[0]);
+        streamversion = (header[0] >> 24) & 15;
+        if (streamversion >= 8) {
+            return false; /* SV8 or higher don't exist yet, so no support */
+        } else if (streamversion == 7) {
+            unsigned int gapless = (header[5] >> 31) & 0x0001;
+            unsigned int last_frame_samples = (header[5] >> 20) & 0x07ff;
+            int track_gain, album_gain;
+            unsigned int bufused;
+            
+            id3->frequency = sfreqs_sv7[(header[2] >> 16) & 0x0003];
+            samples = (uint64_t)header[1]*1152; /* 1152 is mpc frame size */
+            if (gapless)
+                samples -= 1152 - last_frame_samples;
+            else
+                samples -= 481; /* Musepack subband synth filter delay */
+           
+            /* Extract ReplayGain data from header */
+            track_gain = (int16_t)((header[3] >> 16) & 0xffff);
+            id3->track_gain = get_replaygain_int(track_gain);
+            id3->track_peak = ((uint16_t)(header[3] & 0xffff)) << 9;
+            
+            album_gain = (int16_t)((header[4] >> 16) & 0xffff);
+            id3->album_gain = get_replaygain_int(album_gain);
+            id3->album_peak = ((uint16_t)(header[4] & 0xffff)) << 9;
+            
+            /* Write replaygain values to strings for use in id3 screen. We use
+               the XING header as buffer space since Musepack files shouldn't
+               need to use it in any other way */
+            id3->track_gain_string = (char *)id3->toc;
+            bufused = snprintf(id3->track_gain_string, 45,
+                               "%d.%d dB", track_gain/100, abs(track_gain)%100);
+            id3->album_gain_string = (char *)id3->toc + bufused + 1;
+            bufused = snprintf(id3->album_gain_string, 45,
+                               "%d.%d dB", album_gain/100, abs(album_gain)%100);
+        }
+    } else {
+        header[0] = letoh32(header[0]);
+        unsigned int streamversion = (header[0] >> 11) & 0x03FF;
+        if (streamversion != 4 && streamversion != 5 && streamversion != 6)
+            return false;
+        id3->frequency = 44100;
+        id3->track_gain = 0;
+        id3->track_peak = 0;
+        id3->album_gain = 0;
+        id3->album_peak = 0;
+
+        if (streamversion >= 5)
+            samples = (uint64_t)header[1]*1152; // 32 bit
+        else
+            samples = (uint64_t)(header[1] >> 16)*1152; // 16 bit
+
+        samples -= 576;
+        if (streamversion < 6)
+            samples -= 1152;
+    }
+
+    id3->vbr = true;
+    /* Estimate bitrate, we should probably subtract the various header sizes
+       here for super-accurate results */
+    id3->length = ((int64_t) samples * 1000) / id3->frequency;
+
+    if (id3->length <= 0)
+    {
+        logf("mpc length invalid!");
+        return false;
+    }
+
+    id3->filesize = filesize(fd);
+    id3->bitrate = id3->filesize * 8 / id3->length;
+    return true;
+}